Boiler running without a call for heat

mo8414

I have both zones turned off and I noticed my boiler kicked on and opens the zone valve for one of my zones. Even with that zones thermostat taken off its mounting base it still runs so I'm thinking maybe it is the aquastate?

I replaced the L8148j1009 aquastate in February so I'm hoping its not defective but with no other change to the system and me removing the thermostat from its base, the aquastate is probably the culprit.

What are the testing procedures I need to follow with my multimeter to varify how everything is working?

Thanks in advance.

Jamie Hall

It should work the other way around. The thermostat opens the zone valve, and the zone valve requests the boiler. The aquastat will run the boiler — or not — depending on whether the boiler is hot enough.

What you need to do is to disconnect the wires from the thermostat at the zone valve and see if the zone valve closes. It should… If it doesn't, there's a problem in the wiring, assuming the thermostat is off its base.

EdTheHeaterMan

To understand how a thermostat works you need to understand how a light switch works.  When the switch connects the two wires that are connected to the switch, the circuit is completed and the light will illuminate  

Same is true of a thermostat.  When the room temperature drops the thermostat is a switch that turns on the heating system.  When the room gets hotter, the thermostat turns off the switch.  

If for some reason you get the wires to connect when the switch is open (OFF) The lightbulb does not know the switch is off. The light bulb only knows that the electric circuit is complete.  I would look for the wire or thing that is completing the circuit to the zone valve that is open when that zone thermostat is not calling    

HVAC PRO: "How long have you experienced this problem?"

Customer: "Since last Thursday"

Wife: "The day after you hung the new television on the wall"

Customer: "What does hanging the television on the wall have to do with the heater?"

HVAC PRO: "Let me look at that television bracket on the wall"

If you don't get it by now, then you need to hire a pro before you point the parts canon at the problem.

mo8414

Ok im going to find some time to look at it today after work. Im just glad its summer so I don't have to rush it. I'll keep you guys updated, Thanks for all the help.